Help using directx with winforms/wpf

Hi all, so I've been trying to make a level editor using winforms and xna(A total pain in the arse btw) but Ive decided that when it comes to importing the levels into the game itself I'd like the game to utilise the full extent of DX11. This makes using xna quite pointless as any effect I choose to use in the editor would be restricted to dx9. So with this I would like to use DX11 in the editor but still need a good UI environment such as winforms or WPF. The only thing is I've never really mixed managed and unmanaged code before so that's new to me. I see WPF uses d3d to render and can be adapted simple enough but also hear it might be a dead technology and also would require me learning that from scratch. My current level editor is winforms so thought maybe I could switch out xna for a managed directx like slimDX? That way I could still utilise dx11 rendering and exporting would be easier into native dx11 game.

Basically I would just like any advice on which route to take, what your opinions are and preferably links to examples/tutorial/source code that could help.

Thanks in advance for any help.